The grim discovery of Ms Greywind’s body, which showed signs of “homicidal violence”, came days after she was last seen alive, at the apartment of Crews and her partner William Hoehn.

Ms Greywind’s healthy, days-old baby boy was then found at the couple’s apartment in Fargo, North Dakota and they were both charged with conspiracy to commit murder, kidnapping and providing false information to police.

Crews has entered not guilty pleas to the charges, but is now set for a change of plea hearing on Monday. She has previously told police Ms Greywind gave her the baby voluntarily after she helped induce the baby.

But Hoehn, 32, told investigators he arrived at the apartment to find the bathroom full of blood and Crews holding a baby, saying: “This is our baby. This is our family.”

Court documents state Hoehn admitted removing garbage bags containing bloody towels and his own bloody shoes from the apartment and throwing them in an apartment dumpster.

Brooke Crews told police Savanna Greywind gave up her baby.Source:AP

William Hoehn said Crews told him: “This is our baby. This is our family.”Source:AP

Police have not revealed the exact injuries suffered by Ms Greywind, other than to say it was “homicidal violence”.

Before Ms Greywind’s murder, Crews moved from the United States to Australia to marry a man in the Blue Mountains in New South Wales, who she had met on dating site Tagged.

Andrew Murray, a Katoomba chef, said they hit it off online and she moved to Australia in February 2012. “We ended up getting together and getting married,” he told news.com.au.

The trip was the third Crews had made to Australia, after previous visits in 2010 and 2011.

The marriage only lasted a matter of months before she returned to the US in October 2012. Mr Murray said the relationship fell apart when he discovered she had lied about her past, including the fact she had children and had been married before.

Then things took a nasty turn, when she began threatening him, he said. In all, it was six months and 10 days from the time she arrived until she was gone.

“It was all lies, it was all based on lies,” he said. “I didn’t know she was married in America, didn’t know she had children and then it all started coming out. And I said ‘look, I want you to go home and be a mother to your kids.’”

He said she was obsessed with true crime. “She studied psychology and nursing and did her thesis on serial killers. She was always reading books on serial killers and murders and could tell you anything about them.”

Savanna Greywind was looking forward to being a mother, her family say.Source:Supplied

The body of Savanna Lafontaine-Greywind, 22, was found in a river.Source:Supplied

Mr Murray said Crews told him she lost a baby in 2011 and was unable to have children as a result of the miscarriage. “As time passed on, she seemed to get more and more aggressive. “And when I told her go home to be a mother to her kids she started talking about her ex and stuff ... to be honest I thought she might try and get custody of her kids or visitation rights and then [flee] across state lines.”

“She started getting nasty and saying the police wanted to speak to me,” he said. “So I walked in there and said ‘I understand you want to speak to me.’ I gave them my licence [because] I had nothing to hide.”

Brooke Lynn Crews NSW driver's licence. Picture: HPRSource:Supplied

Brooke Lynn Crews is facing court again on Monday.Source:Supplied

The officer denied they were investigating him, but said it was clear something was wrong. “I told them everything,” he said. “I showed them text messages that said the cops were looking for me ... I have immigration paperwork left with false names on it ... When we got married, she used the name Crews as her maiden name, and it isn’t her maiden name.”

He began to delve into her past and discovered she’d been lying. She was furious when he confronted her.

“She just got really aggressive and angry that I had found things out. That’s when she started threatening me with the police. I thought, ‘I’m not scared of you, I’ve done nothing wrong.’”

It was clear she had lived a double life. When she went back to the States, they spoke for two weeks afterwards.

“I was actually thinking of moving over and giving it a go and once she got back to America she just seemed to get really nasty,” he said.

He never imagined she could be violent and was “mortified” when he Googled her name and discovered the allegations against her.

“I just couldn’t believe it to be honest. I had voiced my concerns about her mental state ... but wasn’t expecting that.

“It sort of shocked me to the bone. It’s been five years and I’d shut a lot of things out, but a lot of stuff has come back now.”

When he first saw her picture he thought she had been charged over drink driving or drugs “or something stupid like that”.

“But then I saw what it was. I had to go an make myself a coffee and then go back and look at what I read again.”

She told him she was sending divorce papers, but they never arrived and Mr Murray later visited Births, Deaths and marriages and had the marriage annulled.

“It had been illegal. Crews wasn’t her maiden name and she had falsified her immigration papers.”

After she left Australia he was so concerned about her erratic behaviour he contacted police in both here and in Fargo in the US to alert them.

“I rang the police in North Dakota one night. They just didn’t care. I also went to Sydney and spoke to police about the falsified information. They said they would hand it to the federal police.”

Mr Murray was angry because he thought what allegedly happened was avoidable. “Maybe something could have been done.”

He believed the miscarriage in 2011 could be factor in a factor “in the breakdown”.

Crews wrote letters to her future Australian husband.Source:Supplied

Brooke Lynn Crews immigration documentSource:Supplied

That was the last he heard of her, until a Google search revealed the shocking crimes she’d been charged with. He recognised his wife at once from the media reports. “But she doesn’t look like how she used to. She looks depressed and dishevelled from the photos I’ve seen, whereas she was a happy, bubbly person.”

Mr Murray now believes he was lucky to trust his instincts. “A few people have said that to me. I’ve only told a couple of people and they’ve said the same thing.”

She was never physical or threatening violence, however. “It was mainly, ‘I’m going to get the police on to you’, not ‘I’m going to kill you,’” he said.

He never spoke to any of her relatives and she fell out with his family. “It was good at first but then it soured,” he said. “It made me turn against everyone.”

IN HER OWN WORDS

Old journal entries written by Crews and obtained by a magazine in Fargo reveal what she was thinking in the days leading up to her coming to Australia.

She had just been arrested for attacking her husband Carl Crews with a knife. In an affidavit for a custody of their two children, he wrote that she often ran from her problems and cited the trips to Australia as an example.

His wife, though, denied she fled to NSW to escape the assault charge. In the journal, she wrote of making the decision to leave just before Christmas 2011, a month before the alleged attack.

“My vote is Drew, but this is a double-edged sword” she wrote, referring to Mr Murray, reported HPR. “I can better provide for the family stateside. At the same time, neither of us wants to be in the U.S.”

A calendar she kept in Australia had a note that read, “I love Andrew” with an exclamation point and a heart. Next to it was a note saying they planned to honeymoon in Fiji.

“The time is fast approaching for me to take leave of Oz and head back to the States for a bit. I think back to the time I’ve spent here and I’m amazed at how different I am now compared to when I first arrived … I realise how hard my life is about to become, and surprisingly, I’m ready to face it all.”

William Hoehn, right, appears with his lawyer, Daniel James Borgen, in a hearing this week.Source:AP

She returned to Fargo and became locked into a bitter custody fight over the children. She returned to Australia once more before eventually returning again to the US in 2015. Soon after she left Australia for the last time, she met Hoehn, who had recently been convicted of child neglect and abuse.

Another previous lover, Aaron Edwards, had a child with Crews in 1995. She still owes him thousands of dollars in unpaid child support, and he had no idea where she was until her arrest.

He told news.com.au from his Florida home he and his daughter were stunned at the charges.

“When my daughter was around 14, Brooke found her on Facebook. I talked to her to let her know that I didn't like that they would be talking but also was going to let my daughter make that choice because that was her mother.

“Before that it was probably years of not hearing from her at all.”

Then there was nothing.

“She may have had some brief contact with her on Facebook a few years ago but there hasn’t been any contact other than that.”